The Biden administrations oil and gas lease sale in the Gulf of Mexico last week doesnt just lock in decades of future drilling and greenhouse gas emissions, it also opens up more extraction in an area where chemical companies dumped tons of hazardous industrial waste.

Off the coast of Louisiana, in an area known as Mississippi Canyon, thousands of 55-gallon drums containing decades-old toxic waste remain scattered across a 200-square-mile stretch of ocean floor, as HuffPost revealed earlier this year . Chemical giants received federal permits to dump waste material there in the 1970s, and there has been little oversight of the area in the decades since.

The Environmental Protection Agency has acknowledged it is not monitoring the legacy dumping ground and has little if any understanding of the lingering environmental impacts. In light of HuffPosts reporting, the agency said it had launched an assessment to determine whether the site qualifies for cleanup under the federal Superfund program.

But the decades-old waste hasnt deterred fossil fuel interests in the area. Oil and gas companies are already drilling within the barrel field, with federal agencies allowing them to determine how best to avoid and reduce impacts to existing drums. In fact, it was a Shell drilling plan that shed light on the condition of remaining barrels, noting that many still look intact and may or may not still contain their original content.

During last weeks auction the largest offshore oil and gas lease sale in U.S. history Chevron Corp., Murphy Exploration & Production Co., and Houston Energy LP secured new drilling rights on offshore leasing blocks where barrels have been located.

Chevron paid $256,442.40 to lease two blocks that are part of the dumping ground. Murphy Exploration and Houston Energy paid $154,362.80 and $151,744.80, respectively, to lease one block each.

Those three companies did not respond to HuffPost requests for comment.

As with previous Gulf lease sales, the Bureau of Ocean Energy Management alerted would-be bidders of the inactive industrial waste disposal site in its final sale notice .

The site was established by the [Environmental Protection Agency] in 1973 under the Marine Protection, Research, and Sanctuaries Act to permit the seafloor deposition of approximately 205,000 steel barrels containing chemical wastes and chlorinated hydrocarbons, reads the notice. Bidders and lessees are advised that the blocks associated with the disposal site and adjacent blocks that are included in the sale area may exhibit hazards from barrel contents (toxic, corrosive, and/or potentially explosive materials).

The document lists leasing blocks where barrels are known to exist, but that likely doesnt paint a full picture. Ocean surveys have turned up barrels as far as 10 miles from the designated dump boundary, according to past notices to lessees.